1. Field of the Invention
The present invention relates to a liquid crystal projector device which projects an image having been modulated by a liquid crystal element on a screen.
2. Description of the Related Arts
In conventional, a projector device has been provided, in which a liquid crystal element is used to modulate an image, which is projected on a screen. As such a type of the liquid projector device, those which are configured to modulate three single colored lights including a red (R) light, a green (G) light, and a blue (B) light through modulating elements respectively, has been known.
Here, it has been required to make the image projected on a screen through the liquid crystal projector device to be a high-resolution image, whereby the image is displayed in highly detail. For this reason, attempts have been made (1) to increase a number of the pixels of the liquid crystal element, (2) to construct a multi-display using a plurality of the projector devices and (3) to shift a green (G) pixel to half pixel pitches so that the green pixels are arranged in a doubled manner. The method of shifting a green (G) pixel to half pixel pitches so that the green pixels are arranged in a doubled manner is a method in which the resolution is increased by paying attention to the sensitivity characteristic of the human visibility and is referred to a “dual G system”.
To increase a number of the pixels of the liquid crystal element in order to display an image in high detail, the opening rate of the pixel is decreased, which leads to the lacking of the projection brightness. Also, in a reflecting type liquid crystal element, even if a number of the pixels is increased without decreasing the opening rate, since the lights over the entire region of red, green, and blue (RGB) are connected on a screen by one projection lens, the images for these colors are not to be the same in the strict sense due to the magnification chromatic aberration possessed by the projection lens and, thus, a high-resolution image cannot be obtained.
The multi-display construction is the simplest means for increasing a number of the pixels, but it is difficult to connect the multiple of the displays in a smooth manner. In this construction, due to the variation in the brightness, color reproductivity, gamma characteristics of each projector, the image quality in each display becomes different.
In the case where a green (G) pixel is shifted to half pixel pitches so that the green pixels are arranged in a doubled manner, since the lights over the entire region of red, green, and blue are connected on a screen by one projection lens, the images for these colors are not to be the same in the strict sense due to the magnification chromatic aberration possessed by the projection lens and, thus, no image having high resolution can be obtained.
In an optical unit which provides reflecting type liquid crystal elements for RGB, even if a reflecting type liquid crystal element for green is further added to realize a dual G system, a polarization beam splitter for green light for the additional reflecting type liquid crystal element for green light cannot exhibit sufficient performance for separating polarized light. Accordingly, the image injected from the additional reflecting type liquid crystal element for green light cannot have a sufficient contrast ratio.
The present invention is suggested in light of the above situation and the object of the present invention is to provide a liquid crystal projector device, which realizes high resolution and a sufficient contrast ratio.